Exogenous application of bio-regulators and pinching operations on physiological efficacy, phenology, and productivity of bottle gourd (Lagenaria siceraria (Mol.) Standl)

The research aimed to evaluate the efficacy of varying proportions of bioregulators akin to salicylic acid, Naphthalene Acetic acid (NAA), and biofertisol on pheno-physiological characteristics and productivity of bottle gourd var Pusa Naveen encompassing different levels of pinching operations. The investigation was executed at Vegetable Research Center, Department of Horticulture, JNKVV, Jabalpur, employing twenty-one treatments in factorial Randomized Block Designs during 2021 and 2022. The first factor consisted of three levels: pinching at the 3rd node, pinching at the 6th node, and no pinching. The second factor comprised seven levels: Control (water spray), NAA (100 ppm and 200 ppm), salicylic acid (0.5 millimolar and 0.7 millimolar), and biofertisol (5 mL and 7.5 mL). The interaction between pinching treatments and bioregulators exerted a significant influence on the pheno-physiological attributes and yield performance of bottle gourd. The average data from 2021 to 2022 for phenological, physiological, and yield traits revealed that pinching at 3rd node combined with foliar spray of NAA 200 ppm (P1G2) produced more number of 17.00 female flowers, a narrow sex ratio of 6.67%, maximum fruit set (40.42%), maximum fruit yield of 3.62 kg plant-1, and yield of fruit (253.00q/ha). Pooled data from various treatments indicated that pinching on the 6th node along with foliar application of Biofertisol (7.5 mL) (P2G6) resulted in maximum leaf area duration quanified at 34440.85cm2.days. Pinching at the 3rd node with foliar spray of NAA at 200 ppm (P2G2) led to an increase in the chlorophyll content index, which measured 71.65. Pinching at the 3rd node combined with exogenous application of Salicylic acid (0.5 mM) (P1G3) contributed to an upsurge in the specific leaf area (86.02 cm2g-1) and weight (0.0176 g cm-2). Based on the findings, it could be evinced that pinching at the 3rd node (P1) with exogenous application of NAA 200 ppm improved the performance of phenological and physiological attributes. This was closely succeeded by applying Biofertisol and Salicylic acid, which positively contributed to the performance of Bottlegourd. Overall, the study demonstrates that strategic integration of pinching practices with appropriate bioregulators, particularly pinching at the 3rd node coupled with NAA at 200 ppm, can markedly enhance the pheno-physiological traits and yield potential of bottle gourd.